[PATCH v2 0/6] ACPI: scan: Adjust power management initialization and PCI devices handling

[Rafael J. Wysocki]

Hi All,

This is an update of

https://lore.kernel.org/linux-acpi/3435655.aeNJFYEL58@rafael.j.wysocki/

that adds one patch, drops two patches, and addresses review comments in
some other patches in the series.

The new patch drops an unneeded parent power state update that may lead to
issues in theory from acpi_device_get_power().

One of the patches dropped from the original series is not necessary any
more after addressing review comments in patch [2/6], and the other one
might introduced some issues pointed out by Sashiko.

Overall, the series aims at addressing a few issues present in the core ACPI
device enumeration code, mostly related to the acpi_bus_attach() function.

The first one is that, on some systems, ACPI power management is initialized
twice for devices that have missing dependencies to start with.  An attempt
to address this issue had been made during the 7.3 merge window, but it had
to be reverted [1].  The approach used here is roughly the same as in the
reverted commit, but it takes PCI devices (which are a special case) into
account.

In addition to the above, ACPI power management may be initialized prematurely
for device objects whose parents are not ready for enumeration.

The other issues are that flags are unnecessarily cleared by acpi_bus_attach()
for devices with missing dependencies, the "initialized" ACPI device object
flag is not particularly useful, the "visited" ACPI device object flag is
used for two different things which is confusing at best, and PCI devices
are handled by acpi_bus_attach() like any other devices which is a mistake.

Please see the changelogs of individual patches for details.

Thanks!


Link: https://lore.kernel.org/linux-acpi/20260820-acpi-power-resource-ref-fix-v2-1-29818173ea13@xxxxxxxxxxxxxxxxxx/ [1]